A combustor is a component or area of a gas turbine, ramjet or pulse jet engine where combustion takes place. It is also known as a burner or flame. In a gas turbine engine, the main combustor or combustion chamber is fed high pressure air by the compression system and feeds the hot exhaust into the turbine components of the engine to produce power. The turbine can also be used as a gas generator.
Combustors are designed to contain and control the burning fuel-air mixture. The combustor normally consists of three components: an outer casing that acts as a high pressure container, the combustion chamber itself which contains the flame and the fuel injection system.
There are two categories of combustors, annular and can. Can combustors look like cans and are mounted around the shaft in an engine. They can be easily removed for maintenance and provide convenient plumbing for fuel. Annular combustors are more compact and embedded deep within the engine's casing. Modern jet engines usually have annular combustors.
A main concern in the design of gas turbine combustors is to achieve low pollutant emissions and better pattern factor (uniform thermal field at the combustor exit port). In this regard, modern jet engines with double annular combustors are being introduced to reduce emissions. Additionally, many combustion techniques have been investigated to achieve low pollutants emission (NOx, CO) for gas turbine combustors. Some examples include rich burn—quick quench—lean burn (RQL), catalytic combustion, lean direct injection, and ultra lean premixed combustion.